package _3响应体;
import java.io.*;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/test4")
public class Test4Servlet extends HttpServlet{

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException 
	{
	
		// 告诉客户端我发来的数据是图片
		resp.setContentType("image/jpeg");
		
		// 1. 输入流读取图片
		int id = (int)(Math.random()*3)+1;
		String filePath = getServletContext().getRealPath("/images/"+id+".jpg");
		InputStream in = new FileInputStream(filePath);
		
		// 2. 输出流输出到resp
		OutputStream out = resp.getOutputStream();
		
		byte[] buf = new byte[1024];
		int len=0;
		while((len=in.read(buf))!=-1)
		{
			out.write(buf,0,len);
		}
		
		// 3. 关闭流
		in.close();
		
		
	}
}